repeat_letters_by_numbers.txt

def encode(_)
    str_arr = _.split('')
    return_value = ''
    temp = []
    str_arr.each_with_index do |val, i|
        if val == str_arr[i+1]
            temp << val
        else 
            len = temp.length.zero? ? '' :temp.length + 1
            return_value = [return_value,val,len].join('')
            temp = []
        end
    end
    return_value
end

def decode(_)
    str_arr = _.scan(/\d+|[A-Za-z]+/)
    return_value = ''
    temp = ''
    str_arr.each do | val |
        if val.to_i.zero?
            temp = val
        else
            arr = temp.split('')
            data = arr.pop
            extra_val = arr.join('')
            return_value = return_value + extra_val + data * val.to_i
            temp = ''
        end
    end
    return_value
end

puts encode("aaabbcccabbcc") # => a3b2c3ab2c2
puts decode("a3b2c3ab2c2") # => aaabbcccabbcc
puts decode("a13b12c13ab12c12") # => ?

# puts 'a3b2c3ab22c2'.scan(/\d+|[A-Za-z]+/)

# puts "".methods